Multifunctional and reconfigurable graphene/liquid crystal-assisted asymmetrical Fabry-Pérot cavity for reflected light control.

Abstract

Multifunctional and reconfigurable devices are crucial for compact and smart optoelectronic devices. In this paper, we propose a multifunctional and spectrally reconfigurable asymmetric 1D PhC Fabry-Pérot cavity filled with nematic liquid crystal and bounded by two graphene monolayers. Due to the large number of available degrees of freedom, such a structure can behave as either a notch filter, an absorber, an amplitude modulator, or a phase shifter for the reflected electromagnetic waves. The chemical potential of one or both graphene monolayers can be exploited to modulate the amplitude and phase-shift angle of the reflected electromagnetic waves. Furthermore, all functions are narrowband (1 nm linewidth) and are spectrally tunable over a range of about 200 nm around the working wavelength of 1550 nm by controlling the orientation of the elongated molecules of the liquid crystal. This structure may be advantageously exploited for the realization of optical modulators and beamsteering systems.